telegraph.co.uk

For the last thirty years scientists have believed a giant meteorite that struck Chicxulub in Mexico's Yucatan Peninsula was responsible for the mass extinction of species, including T Rex and its cousins.

But now Professor Gerta Kellera, a geologist at Princeton University, New Jersey, says fossilised traces of plants and animals dug out of low lying hills at El Penon in north east Mexico show this event happened 300,000 years after the dinosaurs disappeared.

Prof Keller believes instead that volcanoes might have killed the dinosaurs.

"Now we find that another catastrophe, which is Deccan Volcanism, which has not had much attention paid to it, may be the real culprit," she said.

The volcanic eruptions happened on India's Deccan plateau between 63 and 67 million years ago, spewing large amounts of sulphur dioxide into the air.

Prof Keller, whose findings are published in the Journal of the Geological Society of London, said: "Not a single species went extinct as a result of the Chicxulub impact."

She said the meteorite, despite having a diameter spanning six miles, seems to have had no effect on any of the plant and animal life of the region whereas the volcanic eruptions could have blocked sunlight, altered climate and caused acid rain.

But she does not believe her research, which has taken twenty years, will stop the raging debate at the heart of the demise of the dinosaurs.

"The decades old controversy over the cause of the mass extinction will never achieve consensus," she said.

Understanding what caused the dinosaurs to disappear remains a great mystery. Theories attempting to explain it include asteroid or cometary impacts, volcanoes, global climate change, rising sea levels and supernova explosions.

Scientists know that at a point about 65 million years ago, some phenomenon triggered mass extinctions on the land and oceans.

Dr Richard Lane, of the US National Science Foundation's division of earth sciences which funded the research, believes Prof Keller's theory is viable.

"Keller and colleagues continue to amass detailed stratigraphic information supporting new thinking about the Chicxulub impact and the mass extinction at the end of the Cretaceous. The two may not be linked after all," he said.